\documentclass[11pt,a4paper,oneside]{article}

\usepackage[english,russian]{babel}
\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{graphicx}
\usepackage{expdlist}
\usepackage{mfpic}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{comment}
\usepackage{listings}
\usepackage{epigraph}
\usepackage{url}
\usepackage{geometry}
\usepackage{longtable}
\usepackage{qtree}

\begin{document}
\input{pages/title.tex}
\input{pages/first.tex}
\input{pages/second.tex}
\input{pages/third.tex}
\end{document}